Clozapine N-oxide Description Metabolite of clozapine. It is 5-HT2 serotonin receptor antagonist. Specifications Cas No. 34233-69-7 Product ID C4759 Product Name Clozapine N-oxide Formula Wt. 342.82 Melting Point 212.0-214.0 Store Temp Ambient References Lin G et al J Pharm Sci 83:1212-7 (1994).